Credit

Caption

False-colour transmission electron micrograph (TEM) of the rod-shaped, gram-negative bacteria Serratia marcescens, showing the characteristic convex curve of the end walls displayed by the 2 bacteria at centre. Species of Serratia occur as commensal fauna in the intestinal mucous membranes of man & mammals. S. marcescens is occasionally pathogenic in humans, presenting in long term, chronically sick patients in whom they may cause septicaemia. Previous medical interest in Serratiasp. Magnification: x12'000 at 35mm, x24'000 at 6x7cm.